LIST OF ABBRIVIATIONS
3.4.4 Data collection
Experimental data were recorded from 40 days of sowing and continued up to harvest.
The following data were recorded during the experimentation.
Crop growth characters i. Plant height (cm) ii. Number of tillers hill-1 iii. Dry weight (g) plant-1
Yield contributing characters i. Length of spike (cm)
ii. Number of spikelets spike-1 iii. Number of grains spike-1 iv. Weight of 1000 grains (g)
Yields and harvest index i. Grain yield (t ha-1) ii. Straw yield (t ha-1) iii. Biological yield (t ha-1) iv. Harvest index (%)
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Detailed procedures of recording data
A brief outline of the data recording procedure is given below:
Crop growth characters
Plant height (cm)
Data on this parameter was recorded at maturity in the expt. 1 and 2, while on two other experiments at 30, 45, 60 and 75 DAS (Days After Sowing) and at harvest as the average of 10 plants selected at random from out site the central 1 m-2 of each plot that were tagged earlier. The height was measured from the ground level to the tip of the plant by a meter scale.
Tillers plant-1
The number of tillers plant-1 was recorded at the time of tillering, booting, heading, anthesis and maturity. Data were recorded by counting tillers from each plant and as the average of 10 plants pre- demarcated plants from each plot.
Phenology of wheat crop
Days required from sowing to heading/anthesis (vegetative stage)
Days required from sowing to anthesis ( 50%) were recorded by calculating the number of days from sowing to starting of anthesis by eye observation of the experimental plots during the experimental period.
Days required from sowing to physiological maturity
Days required from sowing to maturity were recorded by calculating the number of days from sowing to beginning of maturity when spikes become yellow in color by eye observation of the experimental plot.
Days to physiological maturity
Each plot was observed daily for dough stage after milking. Five spike lets were taken randomly from each plot and crushed between thumb and fingers. When from four out of
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five spikelets, milk stops coming out and milk start solidifying in spikelet, was taken as days to dough stage.
Percentage of ground coverage
Percentage of ground coverage was measured by the automatic ground coverage machine named and Chlorophyll content determination was made by the SPAD Meter.
Periodic canopy temperature
Canopy temperature was recorded with the help of infrared thermo meter at 30, 60, 90 and 120 days after sowing of wheat crop. Infrared thermo meter was placed at height of 2 feet above the crop canopy and revolved over the plot and average value of canopy temperature given by the meter was taken as the canopy temperature of the plot. Effective tillers were counted at dough stage of crop. Tillers, which bear ear were counted from one metre row length from four different spots chosen randomly from each plot and were converted to total number of tillers per metre square area. Canopy temperature was measured by the automatic canopy temperature machine named Canopy Temp. Meter.
Ear length
Five ears were selected at random from each plot and their length was measured from tip of last spikelet to base first spikelet and then average value was calculated. Number of grains per ear
Randomly five ears were taken from each plot, ears from lodged crop were also taken on bases of percentage lodging of the plot, threshed manually, counted and averaged for number of grainsspike-1.
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Crop’s reproductive characters
Thousand grain weight (g)
One thousand grains from produce of each plot were taken and their weight was recorded and taken as 1000-grain weight.
Straw yield
Total produce was weighed in bundles after harvesting and four days of sun drying in open. After threshing the weight of grains was subtracted from total bundle weight and remaining was straw yield, which was expressed in tha-1 for presentation.
Grain yield
Bundles of wheat from each plot were threshed separately and grains were collected in separate bags for each plot. After cleaning the grains were weighed and presented in quintals per hectare.
Biological yield
After harvesting and sun drying for four days before threshing wheat bundles were weighted and biological yield was expressed as tha-1.
Harvest index (%)
Harvest index of each plot was calculated separately with grain yield and biological yield obtained from that plot by using the formula.
Fresh and dry weight of grain plant-1
Grains from ten sample plants of each plot were collected at or after anthesis were collected and gently washed with tap water, thereafter soaked with paper towel. Then fresh weight was taken immediately after soaking by paper towel. After taking fresh weight, the sample was
oven dried at 700C for 72 hours. Then oven-dried samples were transferred into a desiccators and allowed to cool down to room temperature, thereafter dry weight of plant was taken and expressed in gm.
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Spike length (cm):
The length of ear was measured with a meter scale from 10 selected spikes and the average value was recorded.
Number of spikes plant-1
The total number of spikes plant-1 was recorded by calculating spikes plant-1. Data on number
of spikes plant-1 were counted from 10 selected plants at harvest and average value was recorded.
Number of Spikelet per spike:
The total number of spikelet spike-1 was counted as the number of spikelet from 10 randomly selected spikes from each plot and average value was recorded.
Number of grains spike-1
The total number of grains spike-1 was counted by adding the number of filled and unfilled grains from 10 randomly selected spikes from each plot and average value was recorded.
The number of grains spike-1 was counted from 5spikes and number of grains spike -1 Filled grains spike-1
The total number of filled grains spike-1 was counted as the number of filled grains from 10 randomly selected spikes from each plot and average value was recorded.
The total number of filled grains spike-1 was counted as the number of filled grains from 10 randomly selected spikes from each plot and average value was recorded.
Unfilled grains spike-1
The total number of unfilled grains spike-1 was counted as the number of unfilled grains from 10 randomly selected spikes from each plot and average value was recorded.
Weight of 1000 grains
One thousand seeds were counted randomly from the total cleaned harvested seeds of each individual plot and then weighed in grams and recorded.
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Grain yield (t ha-1)
Grains obtained from 1.0 m2 of each unit plot were sun-dried and weighed carefully. The dry weight of grains of central 1 m2 area was used to record grain yield m-2 and this was converted into t ha-1 at 12% moisture basis. Grain moisture content was measured by using a digital moisture meter.
Dry weight of grain plant-1
Grains from ten sample plants of each plot were collected at or after anthesis were collected and gently washed with tap water, thereafter soaked with paper towel. Then fresh weight was taken immediately after soaking by paper towel. After taking fresh weight, the sample was oven dried at 700C for 72 hours. Then oven-dried samples were transferred into a desiccators and allowed to cool down to room temperature, thereafter dry weight of plant was taken and expressed in gram.
Straw yield (t ha-1)
Straw obtained from 1.0 m2 of each unit plot were sun-dried and weighed carefully. The dry weight of straws of central 1 m2 area was used to record straw yield m-2 and was converted in to t ha-1.
Biological yield:
Biological yield of a crop is defined as the sum of grain yield and straw yield. The biological yield of wheat was measured for each plot and express in tha-1. The biological yield was estimated with the following formula:
Biological yield = Grain yield + Straw yield Harvest index (%)
It denotes the ratio of economic yield to biological yield and was calculated with the following formula.
X 100
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3.4.5 Evaluating the effect of temperature on physiological, biological and yield